Process for converting petroleum oils



A. D. DAVID PROCESS FOR CONVERTING PETROLEUM OILS Original ile Fe 14, 1923 I Oct. 23, 1928.

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Patented a. 23, 1928.

v 1,688,855 PATENT orrice.

AUBREY 1). D'A'vInor cnIcAeo, ILLINOIS, AssIGNoR To THE UNIVERSAL oII. PROD;-

UCTS COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or sou'rn DAKOTA.

"PROCESS FOR CONVERTING PETROLEUM oILs.

Application filed February 14, 1923, Serial No. 619,038. Renewed April 24, 1928.

This Invention relates to improvements in a process and apparatus for converting petroleum oils and refers more particularly to a process for the continuous destructive distillation of relatively high boiling point products to produce oils of a lower boiling polnt having the characteristics of gasoline.

Among the objects of the invention are to provide a process whereby provison is made for maintaining separated carbon particles produced during conversion in asuspended state and for diverting these suspended prodnets to separate settling tanks to eliminate the necessity of shutting down the apparatus for frequent cleaning, due to the collection and accumulation of deposited carbon; to provide an apparatus for carrying out this process, and in general to provide a process and apparatus of the character referred to.

Fig. 1 is a diagrammatic side elevational view of the apparatus. Fig. 2 is a fragmentary plan view showing in detail the settling tanks. 1

Referring to the drawings at 1 is shown a furnace in which are mounted heating coils 2. The expansion tank 3 is connected to the heating coils by means of a transfer line 4 in which is interposed a valve 5. The expansion or vaporizing tank is connected by means of a vapor line 6 to a dephlegmator 7 which in turn communicates through the line 8 with a condenser coil 9 mounted in a water condenser box 10. The disch rge end of the condenser coil communicates tlirough a line 11 with the receiving tank 12 in which the liquid distillate produced in the system is collected. The

'dephlegmator has a lower leg 7 connected by a pipe 13 controlledby a valve 14 to the charging line 15 which communicates with the heating coils 2. At 17, 18, and 19 are shown settling tanks which are connected with a commonheader 20 which'has connection with the expansion or vaporizing chamber 3 through the drawofi' line 21 controlled by the valve 22. Explaining now the treatment of the oil and its passage'through the apparatus, the charging stock is introduced from any convenient source through the line 15 regulated by the valve 23, and is circulated through the heating coils 2 where it is raised to a conver sion temperature after which it passes through the transfer line in the expansion chamber where it is collected in a considerable body, during which time the conversion and vaporization of the oil takes place.

In the expansion chamber is a circular baffle member 24 positioned at a diagonal and adapted to facilitate the swirling circulation of the oil as is hereinafter explained. Trycocks-25 are tapped into the side of the chamber in order'to ascertain the liquid-level therein) Separate drawofl" lines 26 controlled by valves 27 supply a means for withdrawing the unvaporizet oil from the expansion chamber in case the drawofl' lines to the settling tanks become clogged or obstructed for any reason. A drawofi" line 28 controlled by a valve 29 is connected to the suction side of the pump 30. The discharge side of this pump is connected through a line 31 in the side of the chamber in a manner to produce a swirling action of the liquid oil body in the chamber due to the introduction of liquid products circulated through the pump 30. I

The purpose of ths local circulation is to maintain the oil body in the chamber in a turbulent condition in order that the free carbon separated during the conversion or vaporization of the oil will be held insuspension in the liquid residual substances which are drawn off through the line 21 and directed to the separate settling tanks 17, 18 and 19 through the header 20 and connections 32, 33 and 34icommunicat-ing with the respective tanks. c

The tanks are equipped with trycocks 35 for ascertaining the oil level therein. These tanks may be cut in ancient as desired, and the residual products permitted to collect therein where the oil in stagnant condition permits the'separation of its solid content.

Three tanks are shown in the drawing, but it is understood that any number of tanks may be used according tothe amount of oil'treated and the amount of carbon that is necessary to be eliminated'from the residual liquid withdrawn from the expansion chamber.

At the opposite end of the tanks are drawoif lines from the separate chambers controlled by valves 36 which communicate with the common header 37. The liquid oil with.-

drawn through this line may be directed to any convenient storage not shown, or to fur ther treatment as desired.

The tanks are constructed so "that they may be isolated from the system and the manhole plates at the end removed so that they may be readily cleaned of the deposited carbon.

The local circulation of the liquid products from the expansion chamber through the pump and back intothe expansion chamber assures a turbulent condition of the oil during the vaporizing or conversion riod.

This turbulency not only maintains t e carbon particles in suspension, but also promotes the evolution of the vapors.

It will be readily appreciated b this mode of operation, the apparatus may e operated over a considerable longer period of time, due to the fact that the carbon is collected and separated in separate settling tanks which may be cut out of the system for cleaning, if desired. l

A further advantage is the fact that the oil during its period of conversion in the evap oratin chamber, is maintained in a turbulent condition which increases the cracking action. 1

By treating mid-continent gas oil to temperatures from 700 to 900 F., and at pressures from 50 to 300 pounds, a ood quality distillate of approximately 50 aum is ob tained, and the apparatus can be operated continuously for a much longer time than as heretofore has been possible, due to the fact that carbon deposited is practically eliminated from the system. The apparatus is particularly adapted to conversion of heavy carbon laden oils such as Texas and Mexican oils, and fuel oils due to the fact that these petroleum products are heavily carbon laden, which is easily vseparated out at high temperatures.

I. claim as my invention: 1. A process for treating hydrocarbon oil consisting in raising the'oil to a cracking temperature while advancing in a stream through a heating zone, in transferring the 'highl heated oil to an enlarged reaction cham er wherein a substantial body of oil accumulates and wherein no rise in oil temperature occurs, 'in taking off vapors from .said enlarged chamber for condensation and collection, in continuously withdrawing residual oil from said enlarged chamber without recirculating any portion thereof through p said heating zone, in'maintaining 'a swirling Lesa-8'55 prises continuously removing a portion of the liquid residue from the reaction chamber and isolating such removed portion of the liquidresidue from the apparatus, continuously removing an additional portion of the hot unvaporized liquid residue from the reaction chamber, placing said last mentioned portion of the hot residue under a mechanically imposed pressure and re-introducing the same,

under such mechanically imposed pressure, into said reaction chamber, below the liquid level of the oil therein, but above thepoint' of removalof'the li uid residue fromsaid reaction chamber, and so reintroducing such additional portioncof the hot liquid residue into said reaction chamber that a swirling motion is imparted to the oil body therein, whereby coke-like particles resulting from the cracking reaction are held in sus nsion until removed from the reaction c amber with that portion of the residue whic is isolated from the apparatus.

3. An improvement in a method for crackinn hydrocarbon oil of thejtype in which theoi is heated in a coil and thence transferred to an enlarged reaction chamber body of oil accumulates,v comprisin 'main-, taining a swirling motion of the liquid oil in est wherein a said enlarged chamber to hold the carbon in suspension in the oil by withdrawing a portion of the liquid oil ffiim the chamber and returning it underan increased pressure to said chamber tangential to the wall thereoi,

AUBREY B DAVID, 

